Herz, the unit of frequency

Herz, the unit of frequency

On the previous page you saw that the wavy lines we use to
depict waves are models that help us understand the properties of
waves, like frequency and
wavelength. Waves with a short wavelength have a
high frequency and "change" often.

Oscillation

If you would want to impress your friends you would call this
periodic changing of the wave
"oscillation". When a wave
oscillates once per second we say that it has a
frequency of 1 Herz or Hz.

Another example of frequency is your heart rate. The average
heart of a human at rest beats about 70 times per minute, which
corresponds to a frequency of 70/60 =1.17 beats per second, or 1.17
Hz.

Der Heinrich

The "Herz" was named after Heinrich Herz, a
German phycisit who expanded on the work of James Clerk
Maxwell, the scientist we talked about earlier. Below you see
Heinrich Herz having his picture taken while bathing his feet at a
Tahitian beach.

Now that you now what wavelength and frequency are and how they
are related, it is time to have a closer look at electromagnetic
waves. On the next pages you will learn more about the nature
of electromagnetic waves. Brace yourselves,
because this is where it gets a bit complicated. Let's start of by
looking into how radio waves are generated.